Pressure fluid follow-up servomotor



E. A. ROCKWELL PRESSURE FLUID FOLLOW-UP SERVOMOTOR Aug. 31 1948.

Filed June 4, 1943 4 Sheets-Sheet 1 $2 3 @Q g w v mm 7 l I l I iwm ow ill: 92 lmmr ml 5% $1 w & f lun nn n. In 3 x o a 3 3 0 8 kw mm y? 3 @m m 5 3 5 INVENTOR I Edward H. Rockwell ATTORNEM Aug. 31, 1948. E. A. ROCKWELL PRESSURE FLUID FOLLOW-UP SERVOMOTOR 4 Sheets-Sheet 2 Filed June 4, .1943

Aug. 31, 1948. E. A. ROCKWELL PRESSURE FLUID FOLLOW-UP SERVOMOTOR 4 Sheets-Sheet 3 Filed June 4, 1943 m w m m A m 5 mm m Ms K: mi 5 M 2 mm d Z; & u N Em I g g i M ll, (9 4 Q3 EFNQIWQIi Q 8 m: 44: H Rm Aug. 31, 1948.

E. A. ROCKWELL PRESSURE FLUID FOLLOW-UP SERVOMOTOR Filed June 4, 1943 4 Sheets-Sheet 4 Patented Aug. 31, 1948 UNITED STATES. AT ENT OFFICE PRESSUREFLUID FOBLOW- UP SERVOMOTOR :Edward A. Rockwell, Cleveland, Ohio Application June 4, 1943, Serial No. 489,712

1 Claim. l My invention relates particularly to .-.an :apparatus designed for operating locomotive reverse gears or other parts to be shifted.

The object of my invention is to provide an eflective and inexpensive means for operating H of the above character which will provide a smooth hydraulic control ofthe locomotive reverse gear and which, Whilelnexpensiv-e, will-apply apower means for operating thereversegear while at the same time'eliminati-ng hunting, chattering, etc. Further-objects of myinvention'will appear from the detailed description of the same hereinafter.

' While my invention is capable'of being carried out in many different ways, for-the purposeof illustration I have shown only certain forms of my invention in the accompanying drawings; :in

' which Fig. 1 "is a-sideelevation of a locomotive reverse "gear mechanism made in accordance-withrmy invention; i

Fig.2is an-end elevation ofthesa-me;

Fig. 3 is a vertical section-of the valve used for delivering the hydraulic liquid-under pressure to the controlling mechanism;

Fig. 4 is a longitudinal section of the 'travel control cylinder used therein;

Fig. 5 isa longitudinal section of'the hydraulic cylinder for operating the air orsteam valves;

Fig. 6 isa side elevationof a modified form of manual means for operating the master cylinder;

Fig. 7 is a-section showing the indicaton the section being taken on 'the line of FigJ-G; and

Fig. 8 is -an -elevation showing the indicator operating mechanism of Fig. 6.

Referring first to the construction shown .in

Figs. 1' to '5, I have provided an operating handle l'-which may be located in the cab of a locomotive, the same'being provided with asubs'idiary hand lever 2 pivoted at .3 on the handle l sand .having a pivot 4 connecting it to -a rod 5 normallyprssed downwardly by a coil spring 6 supported on:a lug '1 :on the handle I. The rod-5 actswas .ai pawl to engage a rack-B on asector 9 carriedin fixed position at any point .in the locomotive cats. The sector -9 "has a pivot pin '10 supporting thehand leverl. Furthermore, the-handlever! hasan passes out of the valve casing .4.l:through arllbber .seal' 54 held invplace' by :a washer 155::and :arscrew vcap 56 provided with apackingrfil. Onv therouter end of Lthe1Lpipe 4| Pthere1is;a:nut 58ito hold the ascrewil l in the end of the arm 1'].

arm :I l provided-with a split end l-'2 adapted to be tightened by a nut I3 so asito :lockin place Thescrew 754 has an :adjustable protruding end [5 which .isiaclapted, in its end position,ito contact with thetop ofa valve rod 18, as hereinafter referred to; for liquid compensation.

Thearm l'l, furthermore, has :apivotpin l1 intermediateits ends to whichthereiisconnected .a yoke l8 on a' pistonlrod l9having a piston Ifl-opcrating in amaster cylinder 2 l. Themaster cylinder 2i is closed at'the topby a screw ring cap Illa and has a rubberboot 221betweenthe upper portionthereof and the piston rod l9, nuts 231and :24 being provided to attach the boot -22 to the rod lS by-means of a screw-threaded sleeve 24a. The lower end of the master-cylin'der 2l is :provided with a screw cap25 'having an air-vent 26 and said cap 225 is screw-threaded to a .yoke

it'l -with the aid of a lock nut 28. Said yoke '21,

furthermore, has a pivot pin 29 connecting it to a plate "34 in said yoke havinga stop flange 31 ;overlying a fixed bracket L32, the plate '30-'being con- :nected toaspring-retaining rod 33 slidable in a projection 34 on the fixed bracket 32, having holes 35 for securing the fixed bracket32 onany desired support in the 'cab of the locomotive.

Around: the rod 33 there is a coil spring 36 which is supported by a washer 3i and nuts 38 and 39 on the-lowerend of the rod 33soas to yield-to provide for temperature compensation and to avoid'breakage from the backing up of hydraulic pressure, due to the lever I being held in locked position and the coordination of travel thereof with the work-performing piston referred to hereinafter.

At its upper end the master cylinder 2! "has a'lateral passageway 40 in which-thereis screwthreaded a. pipe 4| having a longitudinal passageway '42 and transverse apertures --43 and44 to connect with alongitudinal passageway 45 in a fitting 46 "through whichthe pipe 41 passes.

The fitting'46 is screw-threaded to a valve casing '4! and has thereina shoulder 48 for supporting a spring 49 which bears at .its upper end against .a valve 5i containing an annular rubber .valve member -52 whichseats against a shoulder 53 on the valve casing 41. A valve stem is connected to thevalve rod lii 'andthe said 'valve'rod l6 valvezcasing 4.1 iniplace andiadjacentxtothe sam there is a screw-thread 59 to receive a nipple 60 having thereon a rubber pipe 6|.

A reservoir pipe fitting 62 is provided on a hand valve casing 63 provided with a hand valve 64 for shutting off the liquid in the pipe 6| when desired. This hand valve casing 63 is screwed into an outlet opening 65 in the bottom of a reservoir 66 adapted to be filled with hydraulic liquid, oil or any other suitable liquid, to be placed under pressure at the top of the reservoir 66 by compressed air supplied through an inlet opening 61 having a hand valve casing 68 containing a hand valve 69 for cutting off the compressed air when desired. The hand valve casing 68 carries a screw fitting 10 connected to a compressed air supply pipe 11 adapted to be provided from any suitable source, as for example the usual compressed air line of a locomotive. Above the valve 52, 53 there is a port 12, controlled by said valve, containing a screw fitting 13 which is connected to a rubber pipe 14, the other end of which is connected to the pipe fitting 62.

A screw fitting 15, located in a supporting pipe bracket 16 having holes 11 for attachment of the same in a fixed position to some part of the cab, is connected to the rubber pipe 6I. The bracket 16, furthermore, has a screw fitting 18 for connecting it to a pressure liquid pipe 19. The pipe 19 is connected by a fitting 80 to a T-pipe joint 8|. The pipe joint BI has a fitting 82 connecting it to a rubber pipe 93 connected by a fitting 84 to a cylinder head 85 having an air bleeder screw 86 of the usual construction. The cylinder head 85, furthermore, has a yoke 81 for connecting it by means of a bolt 88 to a supporting member 89 fastened by means of a nut 90 to a vertical plate 9| which is secured by screws 92 to a cylinder head 93 of a compressed air cylinder 94.

The pressure liquid which is conveyed by the pipe 83 to the cylinder head 85 enters a valve controlling cylinder 95 attached to the head 85 by screws 95. On its interior the cylinder head 85 has a screw-threaded split ring 91 for fastening it, by means of a bolt 98, to a screwrubber packing rings I01 and a retainer ring I08 held in place by a split ring I09 on the intermediate cylinder I 05. The other end of this intermediate cylinder I05 passes out through a forward cylinder head IIO connected to the cylinder 95 by screws III. Adjacent to the cylinder head I I there are a series of rubber packing rings II2 held in place by a ring H3 and a split ring H4. The forward end of the intermediate cylinder IE is provided with a breather opening II4a and is screw-threaded in a split ring end II5 of a pivot bracket II6 held in place by a bolt I I1. Furthermore, adjacent the end of the intermediate cylinder I05 there is a rin H8 for holding in place a retainer ring II9 located in a recess I20 on a head I2I of a piston rod I22, the surface of which is ground to be perfectly cylindrical. The ring H9 has clearances on all sides of it to permit self alignment of the piston I22. The pivot bracket II 6 has a bushby a plug I25 for connecting the bracket II2 to a rocker arm I26 which is fastened on a squared end I21 of a rocker shaft I28, the rocker arm I26 having a split end I29 and bolt I30 for this purpose. The rocker shaft I23 passes through a valve chest gland i3I secured to a rocker housing I 32 by screws I33. At its top the housing I32 has a T-shaped inlet pipe I34 provided with a branch pipe I35 for connection to any suitable source of supply of compressed aid or steam, as for instance the usual compressed air line of the locomotive, and a branch I36 connected by a fitting I31 to a pipe I38 having a screw fitting I39 which is connected to an inlet opening I40 in the cylinder 95 to communicate with an annular chamber ME for returning the piston I06 by compressed air. The annular chamber I 4| may, also, be provided with a water draw-01f cock I4Ia in case steam is used instead of compressed air.

The rocker shaft I28 has thereon a bushing I42 supporting it within the rocker housing I32 and adjacent to the said bushing I42 there is a ring I43 which abuts against a rocker I44 held in place on a screw-threaded squared end I45 of the rocker shaft I23 by a nut I46. The rocker I44 has two arms I41 and I49 which carry vertical slots I49 and I50 to cooperate with a rocker trunnion I5I passing through a rocker trunnion block I52 which is secured to a sliding valve member I53. It will be noted that the rocker housing I32 is connected by bolts I54 to the top of the air cylinder 94 above a fiat extension I55 on the latter, in which there are located a rearwardly directed angular passageway I56 leading to the rear of the cylinder 94 and a similar passageway I51 leading to the front of said cylinder controlled by the valve or valves I53. The sliding valve member I53 has two apertures I58 and I59 to connect alternately with the passageways I56 and I51 so as to convey theretoor therefrom the compressed air or steam admitted from the pipe I35 to the interior of the rocker housing I32, which thus serves as an air or steam chest for this purpose. It will be noted also that the said plate I53 has on the under-face thereof a chamber I60 which is adapted to convey away the exhaust from either of the pipes I56 and I51 when brought into registry therewith, the exhaust being carried away by a passageway I6I leading to an exhaust port I62.

The compressed air thus admitted to either of the ends of the air cylinder 94 acts upon a work-performing piston I63 connected to a piston rod I64 which passes out through a cylinder head I65 having the usual packing gland I66. The said piston rod I64 has at its end a pivot I61 for connectin it to a reach-rod I68 having a pivotal connection I69 to a bell crank lever I10 carried on a fixed pivot "I which in turn has a pivotal connection I12to a lifting link I13 connected in the usual way to a radius rod I 14 adapted to drive the locomotive'in opposite directions bybeing moved into different positions for operating a locomotive reverse gear I14a of any desired type but which may, be, for example, any of the locomotive reverse gears as set forth in Marks Mechanical Engineers Handbook, first edition, 1916, pages 975 to 977, published by McGraw-Hill Book Company, Inc., New

York.

Furthermore, the said piston rod I64 may have attached to the side thereof a diagonal arm I15 which is secured thereto by a bo1t'I16 and nut I11. The lower end of the diagonal rod I15 has at its end I18 a cylindrical rod I19 carried withend'thereof. Along rubberboot I84 is attached tothe-clamp- I8! at one end and is attached at its-otherend to a similar clamp I85having a screw ldfi at its split end and a screwJISI. at

itsbifurcated end, the said bifurcated end being connectedbymeans of the screw" I61 and a supportihgbracketlfiii provided witha screw I89,-from the vertical plate .SI. This clamp I65,

however,lh-as an inlet portllldprovided with a "fitting I9I connected by arrubber pipe I92 to the T-pipe joint 8i. The "clamp I65Jalso has an air bleeder screw I93. Aswwill be noted from 'Fig.-4, thesaid clamp I:85;:has .a cylinder. I84

screw-threaded intothe same,:.Which has:-at its innermost end an. annularr,screw-threadedixhead I95, adjacent-to-which:there a rub-her.;seal

I96 .and an. annular. retaining :plate I91 .adjacent to a bushing I98. This cylinder I94 slides' within an outer cylinder I99 which is screwthreaded in the clamp I (H, a breather opening 200 being provided in said outer cylinder. Furthermore, the foremost end of the outer cylinder I99 abuts against a ring 26I so as to hold in place a ring 262 located in a recess 263 in a plunger 264, the surface of which is ground to be perfectly cylindrical. The ring 262 has clearances on all sides thereof to permit self alignment of the plunger 284. This plunger 204 serves to coordinate the travel of the manual lever I with the rocker lever I 26.

In Figs. 6 to 8 I have shown a modified form of the manual operating mechanism for operating the piston rod I9 and the master cylinder 2|, the parts connected thereto, except the manual means, being just the same as previously described in connection with Figs. 1 to 5. For this purpose, there is attached to the piston rod IS a U-shaped bracket 205 having an arm 206 with a split end 261 provided with a tightening screw 268 in which there is a screw-threaded pin 209 for cooperating with the valve rod I6 for equalizing or compensating the liquid at the end of the forward position of the hand lever I. The U-shaped bracket 205 has provided therein a screw block 2H] through which there is adapted to pass a screw 2I I carried on a hand wheel 2I2 provided with a handle 2I3 for rotating the same. On the wheel 2I2 there is provided a series of notches 2 I4 to receive a tooth =2I5 on a hand lever 2I6 carried by a pivot 2I'I on a fixed bracket 2I8 adapted to be secured by screw 2I9 to any fixed support in the cab. Also on the fixed support 2I8 there may be provided a dial plate 226, secured by screws 22I, having a pointer shaft 222 provided with a rotatable pointer 223 held in place by a screw 224 n a split end 225 on said pointer 223. The shaft 222 extends inwardly through the bracket 2I8 where it is provided with a gear 226 for cooperating with a line gear 221 fastened on the block 2 I c. The line gear 22'! meshes with the side of the gear 2H] so that the postion of the handle 2 I3 is registered by the position of the pointer 223 on the dial 226.

In the operation of my invention, referring first to Figs. 1 to 5, the hand lever I is shown in Fig. 1 in the middle position while the locomotive is at rest. When it is desired to operate the locomotive forwardly the hand lever I is moved to the right, thereupon withdrawing liquid from the cylinder 95 so as to permit the piston I06 to move to the left in Fig. 5, which is followed by the entry of compressed air or steam into the chamber I4I at the rear of said piston I06. This accordingly "positiom-unlthe reverse :gear; whichtwil locomotive torwandly. :This isl accomplishedhzby .theumovernent of: the rockerzleverrtlfi:to :thefleft, -which; accordinglyimoveslthe valve .memberrle53tto the leftsosas tovbringthe:passageways I59; in com- .munioatiomwithlthe passageetiil,nthuswsupplying air sorasteamztof the: right of the; piston; I63; :which shifts the position of the radius rod ltllixi'ntollth drivelfthe accordinglyl moves :to the leftawhile .theileft-send :oftthe:cylinder-:94; is aexhaustedrthroughzzthe ;pas-

:sageway 1 IE'SJand .port 2 I 62. therhandrlever' I inithis: Way: the: nositionztofs the "hand -116V6l I i will. :alWaySf'bB coordinated'zin; travel ':to;-.:the-radiusr rod-:1 I14, (and; thereforathe: reverse U gear mechanism, towing to .the;plunger.204 :moving ;.within the cylinder: I=94ras the:latter istconnectcd bymthe: piperIQZi toa-thetmaster:.cy1inder;Z'I lFfur- In; theroperation: of

thermore, upon the extreme forward movementlof the hand-lever I-thefhand lever I and the radius rod I14 will be brought into phase each time by the opening of' the valve =52, 53,-due to the contact of the screw-end I5with the valve rod. IBand the readjustment in the system. ofthe-v hydraulic liquid or oil received from the reservoir 86 under the influence of the compressed air supplied through the pipe II resulting in passing compensating liquid from the reservoir 66 to the system or in the opposite direction, according to the expansion or contraction of the liquid. When the locomotive is to be driven rearwardly the hand lever is moved to the left of the middle position, shown in Fig. l, whereupon the liquid in the master cylinder 2| will be pressed into the cylinder while the spring 36 is compressed somewhat to avoid undue acceleration, thus moving the rocker lever I26 in the opposite direction to that previously described and, accordingly, conveying the air or steam through the port I58 and passageway I56 to the forward end of the cylinder 94 while simultaneously exhausting the rear end of the cylinder 94 through the passageway I51 and the port I62. Also, during this movement, likewise, the travel of the hand lever I and radius rod I14 are coordinated in the same way. Thus in either direction of drive of the locomotive the engineer will always know the extent of the movement of the radius rod I74 by the position of the hand lever I, and, accordingly, is enabled to control the forward or rearward movement of the locomotive with the greatest degree of precision. Also, the operation of the locomotive in this way takes place with the utmost smoothness and with a minimum of manual effort.

In the operation of the modified manual operating mechanism shown in Figs. 6 to 8, the control of the reverse gear mechanism is carried out in the same way as previously described. However, in this instance the said control is brought about by the movement of the handle 2 I3 on the hand wheel 2I2 after the toothed lever 2I6 has been lifted out of engagement with the locking recesses 2I4. The rotation of the hand wheel 2I2 from its middle position forwardly or rearwardly will brin about the forward or rearward drive of the locomotive, as desired, and the degree of advance forwardly or rearwardly of the hand wheel 2I2 will always be coordinated in travel to the position given to the radius rod I14 and which will be shown at all times by the pointer 223 on the dial 220.

While I have described my invention above in detail I wish it to be understood that many changes may be made therein without departing from the spirit of the same.

I claimt In combination, a part to be shifted, a compressed air power means connected to the said part for shifting the said part, a hydraulically operated manual control means having an adjustable manual lever means and means to hold said lever means in its adjusted position and including a compressed air valve, a hydraulic motor cylinder, having a piston, connected to the air valve and a master cylinder for operating the motor cylinder piston, for controlling the compressed air power means and a hydraulic cylinder connected to the manual control means, having a piston operatively connected to the part to be shifted, said master cylinder having a piston, a manually movable controller attached thereto and a yielding spring upport for the master cylinder to avoid breakage by backed up pressure.

EDWARD A. ROCKWELL.

, REFERENCES CITED The following references are of record in the file of this patent:

Number 8 UNITED STATES PATENTS Name Date Warren Feb. 16, 1904 Lang Sept. 8, 1908 Weight Aug. 9, 1910 Cole Apr. 23, 1912 Rushton Apr. 3, 1917 Adams June 9, 1925 Becker Oct. 18, 1927 Weeks Sept. 19, 1933 Tatter Apr. 20, 1937 La Brie Oct. 12, 1937 Onions Mar. 12, 1940 Gates Aug. 12, 1941 Nardone Dec. 2, 1941 Wheelon Aug. 11, 1942 Meredith Dec. 1, 1942 Kendrick Dec. 15, 1942 Price July 18, 1944 

